Summing Junction Block

Ribbon menu Elements tab Controls Toolkit Standard Control Blocks New/Modify
or
(Classic) Build Controls Toolkit Standard Control Blocks New/Modify
Summing junction blocks add or subtract the outputs from other standard blocks. You can select whether the positive or negative value of an input to a summing junction is used by single-clicking on the +/- sign button.
A summing junction block takes any valid controls block output as its input.
 
For the option:
Do the following:
Name
Enter the name that you want assigned to the function block.
Input 1/
Input 2
Specify the assembly name of any controls block, including input function blocks, in either text box. You can select whether the positive or negative value of the input to a summing junction is used by single-clicking on the +/- sign button. Single-click on the +/- button to select whether the positive or negative value of an input to a summing junction is used.
Check the inputs to the function block.
Display the Information window to review the connections to the block.
Create an output measure. See Controls_measure_panel dialog box help.